Abstract: In order to improve the shale gas well cementing quality and meet the demand of multi-stage fracturing,studies on marine shale gas horizontal well cementing in Pengshui Area were carried out.Based on cementing difficulties for Pengye HF-1 well,we carried out horizontal well casing data simulation analysis based on the tripping data,optimized the stabilizer type and placement space,conducted pressure sealing using the "stress cage" theory to overcome the lost circulation in this section as well as optimized mud flusher and spacer,to meet interface wettability reversal and flushing requirements.Field data showed that,through the numerical simulation analysis and by designing the elastic modulus of elasticity cement slurry to 6.5-8.5 GPa,the end centralization of centralizer reached 67%,which could effectively guarantee the cementing quality and meet the demands of fracturing.CBL logging data showed the acceptance rate of cementing in horizontal section of Pengye HF-1 Well was 78.4%,in line with quality standard,and no interlayer channeling occurred during the fracturing.The research showed that,the technique had guiding significance to cementing in marine shale formation,but adaptability of the technique must be studied further.